JP2019134409A - Magnetoresistive effect device and magnetoresistive effect module - Google Patents

Abstract

To provide a magnetoresistive effect device having excellent blocking characteristics.SOLUTION: A magnetoresistive effect device includes a first port, a second port, a first circuit unit and a second circuit unit connected in series between the first port and the second port, a reference potential terminal, and a DC application terminal, and each of the first circuit unit and the second circuit unit includes a magnetoresistive effect element and a conductor connected to one end thereof, and the first end of the conductor is connected to a high-frequency current input side, and the second end of the first conductor is connected to the reference potential terminal.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a magnetoresistive effect device and a magnetoresistive effect module.

  In recent years, with the enhancement of functions of mobile communication terminals such as mobile phones, the speed of wireless communication has been increased. Since the communication speed is proportional to the bandwidth of the frequency used, the frequency band required for communication is increasing. Accordingly, the number of high frequency filters required for mobile communication terminals is also increasing.

  In recent years, spintronics has been studied as a field that may be applied to new high-frequency components. One of the phenomena attracting attention among them is a ferromagnetic resonance phenomenon caused by a magnetoresistive effect element.

  When an alternating current or an alternating magnetic field is applied to the ferromagnetic layer included in the magnetoresistive element, ferromagnetic resonance can be caused in the magnetization of the ferromagnetic layer. When ferromagnetic resonance occurs, the resistance value of the magnetoresistive element periodically oscillates at the ferromagnetic resonance frequency. This ferromagnetic resonance frequency changes depending on the strength of the magnetic field applied to the ferromagnetic layer, and generally the ferromagnetic resonance frequency is a high frequency band of several to several tens GHz.

  For example, Patent Document 1 describes a magnetoresistive effect device that can be used as a high-frequency device such as a high-frequency filter using a ferromagnetic resonance phenomenon.

JP 2017-063397 A

  However, a high-frequency filter using a magnetoresistive effect device cannot be said to have a sufficient cutoff characteristic.

  The present invention has been made in view of the above problems, and provides a magnetoresistive effect device having excellent blocking characteristics.

In order to solve the above problems, a plurality of circuit units (elements) are connected in series, and each element is connected to a reference potential terminal. It has been found that by satisfying such a connection relationship, the cutoff characteristic of the magnetoresistive device is improved by filtering the power of the input signal a plurality of times.
That is, this invention provides the following means in order to solve the said subject.

(1) A magnetoresistive effect device according to a first aspect includes a first port, a second port, and a first circuit connected in series between the first port and the second port. A unit and a second circuit unit; a reference potential terminal connected to the first circuit unit and the second circuit unit respectively or in common; a first magnetoresistive element of the first circuit unit; A DC application terminal capable of connecting a DC power supply or a DC power supply to each of the second magnetoresistive effect elements of the circuit unit or in common, and the first circuit unit includes a magnetization fixed layer and a magnetization The first magnetoresistive element including a free layer and a spacer layer sandwiched between them, and a first conductor connected to one end of the first magnetoresistive element, wherein the first conductor has a high frequency The current is The first end of the first conductor is connected to a high-frequency current input side, and the second end of the first conductor is connected to the magnetoresistive effect element and the reference potential terminal. The second circuit unit is connected to a reference potential terminal, and the second circuit unit includes a magnetization fixed layer, a magnetization free layer, and a spacer layer sandwiched therebetween, and one end of the second magnetoresistance effect element A second conductor connected to the first conductor of the second conductor so that a high-frequency current branches and flows with respect to the second magnetoresistive effect element and the reference potential terminal. An end is connected to the input side of the high frequency current, and a second end of the second conductor is connected to the reference potential terminal.

(2) In the magnetoresistive effect device according to the aspect described above, the counter electrode connected to the end of the first magnetoresistive element facing the first conductor and the second conductor are formed by a common metal layer. It may be configured.

(3) In the magnetoresistive effect device according to the above aspect, the first magnetoresistive effect element and the second magnetoresistive effect element may be in a parallel connection relationship with respect to the DC application terminal.

(4) In the magnetoresistive effect device according to the aspect described above, the first magnetoresistive effect element and the second magnetoresistive effect element may be in a serial connection relationship with respect to the DC application terminal.

(5) A magnetoresistive effect module according to a second aspect includes the magnetoresistive effect device according to the above aspect, and a DC current source or a DC voltage source connected to the DC application terminal of the magnetoresistive effect device. .

  According to the magnetoresistive effect device according to the above aspect, excellent blocking characteristics can be obtained.

It is the schematic diagram which showed the circuit structure of the magnetoresistive effect module which concerns on 1st Embodiment. It is a schematic diagram which shows the signal characteristic when a 1st circuit unit and a 2nd circuit unit are independent, and the signal characteristic when a 1st circuit unit and a 2nd circuit unit are connected in series. It is the schematic diagram which showed the circuit structure of another example of the magnetoresistive effect module concerning 1st Embodiment. It is the schematic diagram which showed the circuit structure of another example of the magnetoresistive effect module concerning 1st Embodiment. It is the schematic diagram which showed the circuit structure of another example of the magnetoresistive effect module concerning 1st Embodiment. It is the schematic diagram which showed the circuit structure of the modification of the magnetoresistive effect module shown in FIG. It is the schematic diagram which showed the circuit structure of the modification of the magnetoresistive effect module shown in FIG. It is the schematic diagram which showed the circuit structure of the modification of the magnetoresistive effect module shown in FIG. It is the schematic diagram which showed the circuit structure of the modification of the magnetoresistive effect module shown in FIG.

  Hereinafter, the magnetoresistive effect module will be described in detail with reference to the drawings as appropriate. In the drawings used in the following description, in order to make the features easier to understand, the portions that become the features may be shown in an enlarged manner for the sake of convenience, and the dimensional ratios of the respective components may differ from the actual ones. The materials, dimensions, and the like exemplified in the following description are merely examples, and the present invention is not limited to these, and can be implemented with appropriate modifications within the scope of the effects of the present invention.

(First embodiment)
FIG. 1 is a schematic diagram showing a circuit configuration of the magnetoresistive effect module according to the first embodiment. The magnetoresistive effect device includes a first port 1, a second port 2, a first circuit unit 10, a second circuit unit 20, reference potential terminals 3 </ b> A and 3 </ b> B, and a DC application terminal 4. . When the power supply 90 is connected to the DC application terminal 4, the magnetoresistive effect module 100 is obtained. The magnetoresistive effect module 100 receives a signal from the first port 1 and outputs a signal from the second port 2.

<First port and second port>
The first port 1 is an input terminal of the magnetoresistive effect module 100. By connecting an AC signal source (not shown) to the first port 1, an AC signal (high frequency signal) can be applied to the magnetoresistive effect module 100. The high frequency signal applied to the magnetoresistive effect module 100 is a signal having a frequency of 100 MHz or more, for example. The second port 2 is an output terminal of the magnetoresistive effect module 100.

<First circuit unit>
The first circuit unit 10 is connected between the first port 1 and the second port 2. In the first circuit unit 10, a current branching element 11 is incorporated. The current branching element 11 includes a first magnetoresistance effect element 12 and a first conductor 14. The first conductor 14 is connected to one end of the first magnetoresistive element 12 in the stacking direction. The first end 14a of the first conductor 14 is connected to the high-frequency current input side of the first circuit unit 10, and the second end 14b of the first conductor 14 is connected to the reference potential terminal 3A. The high-frequency current _IRC flowing through the first conductor 14 branches and flows to the first magnetoresistance effect element 12 and the reference potential terminal 3A.

<First conductor>
The first conductor 14 functions as an electrode provided in the stacking direction of the first magnetoresistive effect element 12 as well as a wiring for passing a high-frequency current _IRC . The first conductor 14 is made of a conductive material. For example, Ta, Cu, Au, AuCu, Ru, Al, or the like can be used for the first conductor 14. A counter electrode 15 may be provided at the other end of the first magnetoresistive element 12 in the stacking direction. In this case, the counter electrode 15 is connected to the end of the first magnetoresistive element 12 that faces the first conductor 14. As the counter electrode 15, the same electrode exemplified as the first conductor 14 can be used. The other end of the first magnetoresistive element 12 in the stacking direction is connected to the output side of the high-frequency current _IRC in the first circuit unit 10 via the counter electrode 15.

<Magnetoresistance effect element>
The first magnetoresistance effect element 12 includes a magnetization fixed layer 12A, a magnetization free layer 12B, and a spacer layer 12C. The spacer layer 12C is located between the magnetization fixed layer 12A and the magnetization free layer 12B. The magnetization of the magnetization fixed layer 12A is less likely to move than the magnetization of the magnetization free layer 12B, and is fixed in one direction under a predetermined magnetic field environment. The magnetization direction of the magnetization free layer 12B changes relative to the magnetization direction of the magnetization fixed layer 12A, thereby functioning as the first magnetoresistance effect element 12.

  The magnetization fixed layer 12A is made of a ferromagnetic material. The magnetization fixed layer 12A is preferably made of a high spin polarizability material such as Fe, Co, Ni, an alloy of Ni and Fe, an alloy of Fe and Co, or an alloy of Fe, Co and B. By using these materials, the rate of change in magnetoresistance of the first magnetoresistance effect element 12 is increased. The magnetization fixed layer 12A may be made of a Heusler alloy. The thickness of the magnetization fixed layer 12A is preferably 1 to 20 nm.

The magnetization pinning method of the magnetization pinned layer 12A is not particularly limited. For example, an antiferromagnetic layer may be added so as to be in contact with the magnetization fixed layer 12A in order to fix the magnetization of the magnetization fixed layer 12A. Further, the magnetization of the magnetization fixed layer 12A may be fixed using magnetic anisotropy caused by the crystal structure, shape, and the like. For the antiferromagnetic layer, FeO, CoO, NiO, CuFeS ₂ , IrMn, FeMn, PtMn, Cr, Mn, or the like can be used.

  The magnetization free layer 12B is made of a ferromagnetic material whose magnetization direction can be changed by an externally applied magnetic field or a spin-polarized current.

  As a material for the magnetization free layer 12B, CoFe, CoFeB, CoFeSi, CoMnGe, CoMnSi, CoMnAl, FeB, Co, CoCr-based alloy, Co multilayer film, CoCrPt-based alloy, FePt-based alloy, rare earth-containing SmCo-based alloy or TbFeCo alloy, etc. Can be used. The magnetization free layer 12B may be made of a Heusler alloy.

  The thickness of the magnetization free layer 12B is preferably about 0.5 to 20 nm. Further, a high spin polarizability material may be inserted between the magnetization free layer 12B and the spacer layer 12C. By inserting a high spin polarizability material, a high magnetoresistance change rate can be obtained.

  Examples of the high spin polarizability material include a CoFe alloy and a CoFeB alloy. The film thickness of either the CoFe alloy or the CoFeB alloy is preferably about 0.2 to 1.0 nm.

  The spacer layer 12C is a layer disposed between the magnetization fixed layer 12A and the magnetization free layer 12B. The spacer layer 12C is composed of a layer formed of a conductor, an insulator or a semiconductor, or a layer including a conduction point formed of a conductor in the insulator. The spacer layer 12C is preferably a nonmagnetic layer.

  For example, when the spacer layer 12C is made of an insulator, the first magnetoresistive effect element 12 is a tunneling magnetoresistive (TMR) effect element, and when the spacer layer 12C is made of a metal, a giant magnetoresistive (GMR: Giant) is used. Magnetoresistive effect element.

When an insulating material is applied as the spacer layer 12C, an insulating material such as Al ₂ O ₃ , MgO, or MgAl ₂ O ₄ can be used. A high magnetoresistance change rate can be obtained by adjusting the film thickness of the spacer layer 12C so that a coherent tunnel effect appears between the magnetization fixed layer 12A and the magnetization free layer 12B. In order to efficiently use the TMR effect, the thickness of the spacer layer 12C is preferably about 0.5 to 3.0 nm.

  When the spacer layer 12C is made of a conductive material, a conductive material such as Cu, Ag, Au, or Ru can be used. In order to efficiently use the GMR effect, the thickness of the spacer layer 12C is preferably about 0.5 to 3.0 nm.

When the spacer layer 12C is made of a semiconductor material, a material such as ZnO, In ₂ O ₃ , SnO ₂ , ITO, GaO _x or Ga ₂ O _x can be used. In this case, the thickness of the spacer layer 12C is preferably about 1.0 to 4.0 nm.

When a layer including a conduction point constituted by a conductor in the nonmagnetic insulator is applied as the spacer layer 12C, CoFe, CoFeB, CoFeSi, CoMnGe is incorporated into the nonmagnetic insulator constituted by Al ₂ O ₃ or MgO. , CoMnSi, CoMnAl, Fe, Co, Au, Cu, Al, or a structure including a conduction point constituted by a conductor such as Mg or Mg is preferable. In this case, the thickness of the spacer layer 12C is preferably about 0.5 to 2.0 nm.

  A cap layer may be provided between the magnetization free layer 12 </ b> B and the first conductor 14. A seed layer or a buffer layer may be disposed between the first magnetoresistive element 12 and the counter electrode 15. Examples of the cap layer, seed layer, or buffer layer include metal films such as Ru, Ta, Cu, and Cr, oxide films such as MgO, and laminated films thereof. When these layers are made of oxide films, the thickness of these layers is thin enough to allow current to flow. For example, the thickness is preferably such that current (including tunnel current) flows when a voltage of 3 V is applied in the stacking direction of the first magnetoresistive effect element 12, and specifically, it is preferably 5 nm or less. .

  As for the size of the first magnetoresistive element 12, it is desirable that the long side of the first magnetoresistive element 12 in a plan view is 500 nm or less. In addition, it is desirable that the short side of the first magnetoresistive element 12 in a plan view is 50 nm or more. When the planar view shape of the first magnetoresistive effect element 12 is not a rectangle (including a square), the long side of the rectangle circumscribing the planar view shape of the first magnetoresistive effect element 12 with the minimum area is defined as the first magnetic field. The long side of the first magnetoresistive effect element 12 is defined as the long side of the first magnetoresistive effect element 12, and the short side of the rectangle circumscribing the planar view shape of the first magnetoresistive effect element 12 with the minimum area is the plan view shape of the first magnetoresistive effect element 12. It is defined as the short side of.

  When the long side is as small as 500 nm or less, the volume of the magnetization free layer 12B becomes small, and a highly efficient ferromagnetic resonance phenomenon can be realized. Here, the “planar shape” is a shape viewed from the stacking direction of each layer constituting the first magnetoresistance effect element 12.

<Second circuit unit>
The second circuit unit 20 is connected between the first port 1 and the second port 2. The second circuit unit 20 in FIG. 1 is connected between the first circuit unit 10 and the second port 2, and the first circuit unit 10 and the second circuit unit 20 are connected in series. In the second circuit unit 20, a current branching element 21 similar to the current branching element 11 incorporated in the first circuit unit 10 is incorporated.

The current branching element 21 shown in FIG. 1 includes a second magnetoresistance effect element 22 and a second conductor 24. The second conductor 24 is connected to one end of the second magnetoresistive element 22 in the stacking direction. The first end portion 24a of the second conductor 24 is connected to the input side of the high frequency current _{I RC} in the second circuit unit 20, the second end 24b of the second conductor 24 is connected to a reference potential terminal 3B. The high-frequency current _IRC flowing through the second conductor 24 branches and flows to the second magnetoresistive element 22 and the reference potential terminal 3B. The second magnetoresistive element 22 has a magnetization fixed layer 22A, a magnetization free layer 22B, and a spacer layer 22C. The second conductor 24 is at one end in the stacking direction, and the counter electrode 25 is at the other end in the stacking direction. Is provided. As the second magnetoresistance effect element 22, the second conductor 24, and the counter electrode 25, the same ones as exemplified for the first magnetoresistance effect element 12, the first conductor 14, and the counter electrode 15 are used. In FIG. 1, the second conductor 24 is connected to the counter electrode 15 of the first circuit unit 10 by the via wiring 95. The other end of the second magnetoresistive element 22 in the stacking direction is connected to the output side (second port 2) of the high-frequency current _IR in the second circuit unit 20 via the counter electrode 25.

<Reference potential terminal>
The reference potential terminals 3A and 3B are connected to the first circuit unit 10 and the second circuit unit 20, respectively. The reference potential terminals 3A and 3B are connected to the reference potential and determine the reference potential of the magnetoresistive effect module 100. In FIG. 1, the reference potential is connected to the ground GND. The ground GND is provided outside the magnetoresistive effect module 100. In FIG. 1, the reference potential terminal 3 </ b> A is connected to the first circuit unit 10 via a capacitor 94 (connected in an alternating manner (high frequency)), and the reference potential terminal 3 </ b> B is connected to the second circuit unit 20. Has been. In FIG. 1, the reference potential terminal 3 </ b> B is connected to the first circuit unit 10 via the second circuit unit 20. The high-frequency current _IRC input to the first port 1 flows in the first circuit unit 10 and the second circuit unit 20 according to the potential difference from the reference potential. In FIG. 1, the reference potential terminal 3 is provided separately for each of the first circuit unit 10 and the second circuit unit 20, but is shared by the first circuit unit 10 and the second circuit unit 20. (For example, a modified example to be described later).

<DC application terminal>
The DC application terminal 4 is connected to a power supply 90 and applies a DC current or a DC voltage in the stacking direction of the first magnetoresistance effect element 12 and the second magnetoresistance effect element 22. The first magnetoresistance effect element 12 is connected to a DC application terminal 4 to which a power supply 90 for applying a DC current or a DC voltage to the first magnetoresistance effect element 12 can be connected. The second magnetoresistance effect element 22 is connected to the DC application terminal 4 to which a power supply 90 for applying a DC current or a DC voltage to the second magnetoresistance effect element 22 can be connected. In this specification, the direct current is a current whose direction does not change with time, and includes a current whose magnitude changes with time. The DC voltage is a voltage whose direction does not change with time, and includes a voltage whose magnitude changes with time. The power supply 90 may be a DC current source or a DC voltage source. The power supply 90 may be a direct current source capable of generating a constant direct current or a direct current voltage source capable of generating a constant direct current voltage. The power source 90 may be a direct current source capable of changing the magnitude of the generated direct current value, or may be a direct current voltage source capable of changing the magnitude of the generated direct current voltage value. In the magnetoresistive effect module 100 shown in FIG. 1, the flow directions of the direct currents flowing through the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 are the same, and the direct current is the magnetization free layer 12B, It flows in the order of 22B, spacer layers 12C and 22C, and magnetization fixed layers 12A and 22A.

  The current density of the direct current applied to the first magnetoresistance effect element 12 and the second magnetoresistance effect element 22 is smaller than the oscillation threshold current density of the first magnetoresistance effect element 12 and the second magnetoresistance effect element 22. Is preferred. The oscillation threshold current density of the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 is that a current having a current density equal to or higher than this value is applied so that the magnetizations of the magnetization free layers 12B and 22B have a constant frequency and Precession starts with a constant amplitude, and the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 oscillate (the outputs (resistance values of the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22). ) Is the current density of the threshold (which fluctuates at a constant frequency and a constant amplitude).

<Other configurations>
The magnetoresistive effect module 100 is provided with an inductor 92 and a capacitor 94. The inductor 92 cuts the high frequency component of the current and passes the current invariant component. The capacitor 94 passes the high frequency component of the current and cuts the invariant component of the current. The inductor 92 is disposed in the portion to be suppressed flow of high frequency current I _RC, capacitor 94 is arranged in the portion to be suppressed DC current flow. In FIG. 1, the inductor 92 suppresses the high-frequency current applied from the first port 1 from flowing to the reference potential and dissipating. Further, the capacitor 94 suppresses the direct current applied from the power source 90 from flowing and dissipating to the first port 1 and the second port 2, and the direct current applied from the power source 90 is connected to the reference potential terminal. The flow from 3A to the first conductor 14 is suppressed.

  As the inductor 92, a chip inductor, an inductor using a pattern line, a resistance element having an inductor component, or the like can be used. The inductance of the inductor 92 is preferably 10 nH or more. A known capacitor can be used as the capacitor 94.

  Each circuit unit and each terminal are connected by a signal line. The shape of the signal line is preferably defined as a microstrip line (MSL) type or a coplanar waveguide (CPW) type. When designing the microstrip line (MSL) type or the coplanar waveguide (CPW) type, it is preferable to design the line width and the distance between the grounds so that the characteristic impedance of the signal line is equal to the impedance of the circuit system. . By designing in this way, the transmission loss of the signal line can be suppressed.

  The magnetoresistive effect module 100 preferably has a frequency setting mechanism 80. The frequency setting mechanism 80 is a magnetic field application mechanism that applies an external magnetic field, which is a static magnetic field, to the first magnetoresistive element 12 and the second magnetoresistive element 22. The frequency setting mechanism 80 sets the ferromagnetic resonance frequencies of the magnetization free layers 12B and 22B of the first magnetoresistive element 12 and the second magnetoresistive element 22. The frequency of the signal output from the magnetoresistive effect module 100 varies depending on the ferromagnetic resonance frequency of the magnetization free layers 12B and 22B. That is, the frequency of the output signal can be set by the frequency setting mechanism 80.

  The frequency setting mechanism 80 may be provided in each of the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 or may be provided in common. The frequency setting mechanism 80 is configured by, for example, an electromagnet type or stripline type magnetic field application mechanism that can variably control the applied magnetic field intensity by either voltage or current. Moreover, it may be configured by a combination of an electromagnet type or stripline type magnetic field application mechanism capable of variably controlling the applied magnetic field intensity and a permanent magnet that supplies only a constant magnetic field.

<Function of magnetoresistive device>
When a high frequency signal is input to the magnetoresistive effect module 100 from the first port 1, a high frequency current _IRC corresponding to the high frequency signal flows through the first circuit unit 10. The high-frequency current _IRC branches and flows to the first magnetoresistance effect element 12 and the reference potential terminal 3A.

The magnetization of the magnetization free layer 12 </ b> B mainly oscillates by receiving a high frequency magnetic field generated by the high frequency current _IRC flowing through the first conductor 14. The magnetization of the magnetization free layer 12B by the ferromagnetic resonance phenomenon, the frequency of the high frequency current I _RC is, large vibration when near the ferromagnetic resonance frequency of the magnetization free layer 12B. When the vibration of magnetization of the magnetization free layer 12B increases, the resistance value change in the first magnetoresistance effect element 12 increases. This change in resistance value is output from the first magnetoresistance effect element 12 (first circuit unit 10) by applying a direct current in the stacking direction of the first magnetoresistance effect element 12. The sum of the output due to the change in resistance value caused by the ferromagnetic resonance phenomenon and the output due to the high-frequency current _IRC branched and flowing to the first magnetoresistive effect element 12 is the first magnetoresistive effect element 12 (first circuit unit). 10).

Next, the high-frequency current I _RC output from the first circuit unit 10 flows to the second circuit unit 20. In the second circuit unit 20, as in the first circuit unit 10, the high-frequency current _IRC branches and flows to the second magnetoresistance effect element 22 and the reference potential terminal 3B. Then, the magnetization magnetization of the free layer 22B, the frequency of the high frequency current I _RC is, large vibration when near the ferromagnetic resonance frequency of the magnetization free layer 22B.

When the vibration of magnetization of the magnetization free layer 22B increases, the resistance value change in the second magnetoresistive element 22 increases. This change in resistance value is output from the second magnetoresistance effect element 22 (second circuit unit 20) by applying a direct current in the stacking direction of the second magnetoresistance effect element 22. The sum of the output due to the change in resistance value caused by the ferromagnetic resonance phenomenon and the output due to the high-frequency current _IRC branched and flowing to the second magnetoresistance effect element 22 is the second magnetoresistance effect element 22 (second circuit unit). 20) and output from the second port 2.

  That is, when the frequency of the high-frequency signal input from the first port 1 is in the vicinity of the ferromagnetic resonance frequency of the magnetization free layers 12B and 22B, the resistance values of the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 A large amount of fluctuation is output from the second port 2. On the other hand, when the frequency of the high-frequency signal deviates from the ferromagnetic resonance frequency of the magnetization free layers 12B and 22B, the fluctuation amount of the resistance value of the first magnetoresistive element 12 and the second magnetoresistive element 22 is small. The output due to the resistance value change caused by the ferromagnetic resonance phenomenon is hardly output from the second port 2.

  2 shows signal characteristics when the first circuit unit 10 and the second circuit unit 20 are independent, and signal characteristics of the magnetoresistive effect module 100 in which the first circuit unit 10 and the second circuit unit 20 are connected in series. It is a schematic diagram which shows. The signal characteristics correspond to the ratio of output power to input power. As shown in FIG. 2, the first circuit unit 10 and the second circuit unit 20 independently exhibit anti-low lentian signal characteristics. The anti-Lorrentian signal characteristic is a signal characteristic that can be fitted by an anti-symmetric Cauchy-Lorentz distribution. The anti-Lorrentian signal characteristic has two peaks: a peak that improves the pass characteristic and a peak that decreases. Is a signal characteristic.

  As shown in FIG. 2, the signal characteristic of the magnetoresistive effect module 100 in which the first circuit unit 10 and the second circuit unit 20 are connected in series uses the first circuit unit 10 and the second circuit unit 20 alone. Compared to the signal characteristics in the case of the This is considered due to the fact that the second end portion 14b of the first conductor 14 and the second end portion 24b of the second conductor 24 are connected to the reference potential terminals 3A and 3B, respectively.

As for the frequency deviating from the ferromagnetic resonance frequency of the magnetization free layer 12B, the output by the high frequency current _IRC branched and flowing to the first magnetoresistive effect element 12 is output from the first circuit unit 10 and the second circuit unit 20 Is input. The high-frequency current _IRC input to the second circuit unit 20 branches and flows to the second magnetoresistance effect element 22 and the reference potential terminal 3B. With respect to the frequency deviating from the ferromagnetic resonance frequency of the magnetization free layer 22B, the output by the high frequency current _IRC branched and flowing to the second magnetoresistive effect element 22 is output from the second circuit unit 20 and the second port 2 Is output from.

The high frequency current I _RC having a frequency deviating from the ferromagnetic resonance frequency of the magnetization free layer 12B and the ferromagnetic resonance frequency of the magnetization free layer 22B is expressed by the first circuit unit 10 (current branching element 11) and the second circuit unit 20 ( Each time it branches in the current branching element 12), it becomes smaller. As a result, the output from the second port 2 is small for frequencies that are out of the ferromagnetic resonance frequency of the magnetization free layer 12B and the ferromagnetic resonance frequency of the magnetization free layer 22B. Thus, the interruption characteristic of the magnetoresistive effect module 100 is improved by repeating the branching of the high-frequency current _IRC . The signal characteristics of the magnetoresistive effect module 100 are excellent in cutoff characteristics in a frequency region other than the passband. Utilizing this signal characteristic, the magnetoresistive effect module 100 (or magnetoresistive effect device) can be used as a high frequency filter that can selectively pass a high frequency signal of a specific frequency.

  Here, the relationship between the ferromagnetic resonance frequencies of the magnetization free layer 12B of the first magnetoresistance effect element 12 and the magnetization free layer 22B of the second magnetoresistance effect element 22 is not particularly limited. When the two ferromagnetic resonance frequencies are the same or close to each other, the passband width is narrowed, and the difference (ΔS21) between the pass characteristic and the cutoff characteristic is increased. On the other hand, when the two ferromagnetic resonance frequencies are separated from each other, the passband width is increased and ΔS21 is decreased. Therefore, it can design suitably according to the use and use aspect calculated | required.

  Although the embodiments of the present invention have been described in detail with reference to the drawings, the configurations and combinations of the embodiments in the embodiments are examples, and the addition and omission of configurations are within the scope not departing from the gist of the present invention. , Substitutions, and other changes are possible.

In FIG. 1, the first circuit unit 10 and the second circuit unit 20 are connected in series, but three or more current branching elements (three or more circuit units including current branching elements) are connected in series. May be. In this configuration, since the branching of the high-frequency current _IR is repeated, the cutoff characteristic of the magnetoresistive effect module is further improved.

  FIG. 3 is a schematic view showing a circuit configuration of another example of the magnetoresistive effect module according to the first embodiment. 3, the same components as those in FIG. 1 are denoted by the same reference numerals. The magnetoresistive effect module 101 shown in FIG. 3 is that the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 share the DC application terminal 4 and the power supply 90. Different from the effect module 100. Since the DC application terminal 4 and the power source 90 are shared, the magnetoresistive effect module 101 has a simplified element configuration and can be reduced in size.

In the magnetoresistive effect module 101 shown in FIG. 3, the counter electrode 25 is connected to the reference potential terminal 3 </ b> C via the inductor 92. Further, between the first port 1 and the first end portion 14a of the first conductor 14, between the second end portion 14b of the first conductor 14 and the reference potential terminal 3A, and the second end portion of the second conductor 24. A capacitor 94 is provided between 24 b and the reference potential terminal 3 </ b> B and between the counter electrode 25 and the second port 2. In FIG. 3, the reference potential terminal 3 </ b> A is connected to the first circuit unit 10 via a capacitor 94 (connected in an alternating manner (high frequency)), and the reference potential terminal 3 </ b> B is connected to the second circuit unit 10 via a capacitor 94. It is connected to the circuit unit 20 (connected in alternating current (high frequency)). In FIG. 3, the reference potential terminal 3 </ b> C is connected to the second circuit unit 20 via the inductor 92 (directly connected). In FIG. 3, the reference potential terminal 3 </ b> C is connected to the first circuit unit 10 via the inductor 92 and the second circuit unit 20 (directly connected). The direct current applied from the power supply 90 is suppressed by the capacitor 94 from flowing from the reference potential terminal 3A to the first conductor 14, and from flowing from the reference potential terminal 3B to the second conductor 24, and the first magnetic resistance It flows to the effect element 12 and the second magnetoresistive effect element 22. The first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 are connected in series with the DC application terminal 4 as a reference, and the DC current applied from the power supply 90 is applied to the counter electrode 25 and the second magnetoresistive effect element. 22, the second conductor 24, the via wiring 95, the counter electrode 15, and the first magnetoresistive element 12 flow in this order. Further, the flow of the high-frequency current _IRC is the same as that shown in FIG. Therefore, the magnetoresistive effect module 101 shown in FIG.

  FIG. 4 is a schematic diagram showing a circuit configuration of another example of the magnetoresistive effect module according to the first embodiment. In FIG. 4, the same components as those in FIG. The magnetoresistive effect module 102 shown in FIG. 4 is that the counter electrode 15 of the first magnetoresistive effect element 12 and the second conductor 24 of the second magnetoresistive effect element 22 are a common metal layer 30 in FIG. It differs from the magnetoresistive effect module 101 shown. In FIG. 4, the reference potential terminal 3 </ b> A is connected to the first circuit unit 10, and the reference potential terminal 3 </ b> B is connected to the second circuit unit 20 via a capacitor 94 (AC (high frequency) connection). Have been). In FIG. 4, the reference potential terminal 3 </ b> C is connected to the second circuit unit 20 via the inductor 92 (directly connected).

  In the magnetoresistive effect module 102 shown in FIG. 4, since the counter electrode 15 and the second conductor 24 are common, it is not necessary to connect these via the via wiring 95 (see FIG. 1). The via wiring 95 can contribute to an increase in element resistance. Since the counter electrode 15 and the second conductor 24 become a common metal layer 30, an increase in element resistance can be suppressed. Further, a space for providing the via wiring 95 is not necessary, and the magnetoresistive effect module 102 can be downsized.

  In the magnetoresistance effect module 102 shown in FIG. 4, the first magnetoresistance effect element 12 and the second magnetoresistance effect element 22 are stacked on the same surface of the metal layer 30. The first magnetoresistive element 12 and the second magnetoresistive element 22 may be connected to different surfaces of the metal layer 30, but are preferably stacked on the same surface of the metal layer 30.

  When the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 are stacked on the same surface of the metal layer 30, the magnetoresistive effect module 102 can be easily manufactured. The first magnetoresistive element 12 and the second magnetoresistive element 22 have the same stacking order of the magnetization fixed layers 12A and 22A, the spacer layers 12C and 22C, and the magnetization free layers 12B and 22B. That is, a layer that becomes the first magnetoresistance effect element 12 and the second magnetoresistance effect element 22 is laminated on the metal layer 30 in which the counter electrode 15 and the second conductor 24 are shared, and unnecessary portions are formed by a technique such as photolithography. By removing, the 1st magnetoresistive effect element 12 and the 2nd magnetoresistive effect element 22 can be manufactured at once.

  In the magnetoresistive effect module 102 shown in FIG. 4, the first end 30 a of the metal layer 30 is connected to the DC application terminal 4. Further, the capacitor 94 is provided between the first port 1 and the first end 14a of the first conductor 14, between the second end 30b of the metal layer 30 and the reference potential terminal 3B, and between the counter electrode 25 and the second end. Between the two ports. Since the capacitor 94 is disposed at the position, the direct current applied from the power source 90 is applied from the reference potential terminal 3A through the first conductor 14, the first magnetoresistive effect element 12, and the metal layer 30. The current flows to the terminal 4 and flows from the reference potential terminal 3 </ b> C to the DC application terminal 4 through the inductor 92, the counter electrode 25, the second magnetoresistive effect element 22, and the metal layer 30. That is, the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 are connected in parallel with the DC application terminal 4 as a reference, and the DC current applied from the power source 90 is the first magnetoresistive effect element 12. And flow into the second magnetoresistive element 22. The direction of the direct current flowing through the first magnetoresistive element 12 and the second magnetoresistive element 22 is the same, and the direct current flows from the magnetization free layers 12B and 22B, the spacer layers 12C and 22C, and the magnetization fixed layer. It flows in the order of 12A and 22A.

  FIG. 5 is a schematic diagram showing a circuit configuration of another example of the magnetoresistive effect module according to the first embodiment. In FIG. 5, the same components as those in FIG. The magnetoresistive effect module 103 shown in FIG. 5 has the magnetoresistive effect shown in FIG. 4 in that the first magnetoresistive effect element 12 and the second magnetoresistive effect element 22 are connected in series with the DC application terminal 4 as a reference. Different from module 102. In FIG. 5, the reference potential terminal 3 </ b> A is connected to the first circuit unit 10 via a capacitor 94 (connected in an alternating manner (high frequency)), and the reference potential terminal 3 </ b> B is connected to the second circuit unit 10 via a capacitor 94. It is connected to the circuit unit 20 (connected in alternating current (high frequency)). In FIG. 5, the reference potential terminal 3 </ b> C is connected to the second circuit unit 20 via the inductor 92 (directly connected). In FIG. 5, the reference potential terminal 3 </ b> C is connected to the first circuit unit 10 via the inductor 92 and the second circuit unit 20 (connected in a direct current manner).

  In the magnetoresistive effect module 103 shown in FIG. 5, the first end portion 14 a of the first conductor 14 is connected to the DC application terminal 4. The capacitor 94 is connected between the first port 1 and the first end 14a of the first conductor 14, between the second end 14b of the first conductor 14 and the reference potential terminal 3A, and between the first end 14a of the metal layer 30. It is provided between the two end portions 30b and the reference potential terminal 3B and between the counter electrode 25 and the second port 2. Since the capacitor 94 is disposed at the position, the direct current applied from the power supply 90 flows in the order of the first magnetoresistance effect element 12, the metal layer 30, and the second magnetoresistance effect element 22. The direction of the direct current flowing inside the first magnetoresistive element 12 and the second magnetoresistive element 22 is opposite. In the first magnetoresistive element 12, the magnetization free layer 12B, the spacer layer 12C, and the magnetization fixed layer The second magnetoresistance effect element 22 flows in the order of the magnetization fixed layer 22A, the spacer layer 22C, and the magnetization fixed layer 22A.

In the magnetoresistive effect modules 102 and 103 shown in FIGS. 4 and 5, the inductor 92 is provided between the first port 1 and the DC application terminal 4 and between the second port 2 and the reference potential terminal 3C. It has been. The high-frequency current I _RC input from the first port 1 branches to the reference potential terminals 3A and 3B side at the second end 14b of the first conductor 14 and the second end 30b of the metal layer 30, respectively. It flows through each of the magnetoresistive effect element 12 and the second magnetoresistive effect element 22. Therefore, also in the magnetoresistive effect modules 102 and 103 shown in FIG. 4及図5, high-frequency current _{I RC} branch is repeated, cutoff characteristics can be improved.

FIG. 6 is a schematic diagram showing a circuit configuration of a modification of the magnetoresistive effect module 100 shown in FIG. FIG. 7 is a schematic diagram showing a circuit configuration of a modified example of the magnetoresistive effect module 101 shown in FIG. FIG. 8 is a schematic diagram showing a circuit configuration of a modification of the magnetoresistive effect module 102 shown in FIG. FIG. 9 is a schematic diagram showing a circuit configuration of a modified example of the magnetoresistive effect module 103 shown in FIG. In the magnetoresistive effect modules 100A, 101A, 102A, and 103A shown in FIGS. 6 to 9, the reference potential terminal 3 is combined into one for the first circuit unit 10 and the second circuit unit 20. A power supply 90 is incorporated in the circuits of the magnetoresistive effect modules 100A, 101A, 102A, and 103A. Even in the configurations of these modified examples, the branching of the high-frequency current _IR is repeated, and the cutoff characteristic is improved.

  The inductor 92 in the above embodiment can be changed to a resistance element. This resistance element has a function of cutting a high frequency component of a current by a resistance component. This resistance element may be either a chip resistance or a resistance by a pattern line. The resistance value of this resistance element is preferably equal to or greater than the characteristic impedance of the signal line output from the magnetoresistive effect element. For example, when the characteristic impedance of the signal line is 50Ω and the resistance value of the resistance element is 50Ω, 45% of high frequency power can be cut by the resistance element. When the characteristic impedance of the signal line is 50Ω and the resistance value of the resistance element is 500Ω, 90% of high frequency power can be cut by the resistance element. Even in this case, the output signal output from the magnetoresistive effect element can be efficiently supplied to the second port 2.

  In the above embodiment, when the power supply 90 connected to the DC application terminal 4 has a function of cutting the high frequency component of the current and passing the current invariant component at the same time, the inductor 92 may be omitted. Even in this case, the output signal output from the magnetoresistive effect element can be efficiently supplied to the second port 2.

  Moreover, although the said embodiment demonstrated based on the example which uses the frequency setting mechanism 80 as a magnetic field application mechanism, the following other examples can also be used for the frequency setting mechanism 80. FIG. For example, an electric field application mechanism that applies an electric field to the magnetoresistive effect element may be used as the frequency setting mechanism. When the electric field applied mechanism changes the electric field applied to the magnetization free layer of the magnetoresistive element, the anisotropic magnetic field in the magnetization free layer changes, and the effective magnetic field in the magnetization free layer changes. Then, the ferromagnetic resonance frequency of the magnetization free layer is set.

  For example, a piezoelectric body and an electric field application mechanism may be combined as the frequency setting mechanism. A piezoelectric body is provided in the vicinity of the magnetization free layer of the magnetoresistive effect element, and an electric field is applied to the piezoelectric body. The piezoelectric body to which the electric field is applied is deformed and distorts the magnetization free layer. When the magnetization free layer is distorted, the anisotropic magnetic field in the magnetization free layer changes, and the effective magnetic field in the magnetization free layer changes. Then, the ferromagnetic resonance frequency of the magnetization free layer is set.

  For example, as the frequency setting mechanism, a control film that is an antiferromagnetic material or a ferrimagnetic material having an electromagnetic effect, a mechanism that applies a magnetic field to the control film, and a mechanism that applies an electric field to the control film may be used. . An electric field and a magnetic field are applied to a control film provided to be magnetically coupled to the magnetization free layer. When at least one of an electric field and a magnetic field applied to the control film is changed, the exchange coupling magnetic field in the magnetization free layer changes, and the effective magnetic field in the magnetization free layer changes. Then, the ferromagnetic resonance frequency of the magnetization free layer is set.

  Further, even if there is no frequency setting mechanism 80 (even if a static magnetic field is not applied from the magnetic field application mechanism), if the ferromagnetic resonance frequency of the magnetization free layer of the magnetoresistive effect element is a desired frequency, the frequency setting mechanism 80 It is not necessary to have.

<Other uses>
Moreover, although the case where a magnetoresistive effect device is used as a high frequency filter was shown as an example above, the magnetoresistive effect device can also be used as a high frequency device such as an amplifier.

  When the magnetoresistive effect device is used as an amplifier, the direct current or direct current voltage applied from the power supply 90 is set to a predetermined magnitude or more. By doing in this way, the signal output from the 2nd port 2 becomes larger than the signal input from the 1st port 1, and it functions as an amplifier.

  As described above, the magnetoresistive effect device can function as a high-frequency device such as an amplifier.

DESCRIPTION OF SYMBOLS 1 1st port 2 2nd port 3A, 3B, 3C Reference potential terminal 4 DC application terminal 10 1st circuit unit 20 2nd circuit unit 11, 21 Current branch type | mold element 12 1st magnetoresistive effect element 22 2nd magnetism Resistance effect elements 12A, 22A Magnetization fixed layers 12B, 22B Magnetization free layers 12C, 22C Spacer layer 14 First conductor 24 Second conductor 30 Metal layers 14a, 24a, 30a First end portions 14b, 24b, 30b Second end portion 15 , 25 Counter electrode 80 Frequency setting mechanism 90 Power supply 92 Inductor 94 Capacitors 100, 101, 102, 103, 100A, 101A, 102A, 103A Magnetoresistive effect module

Claims (5)

A first port;
A second port;
A first circuit unit and a second circuit unit connected in series between the first port and the second port;
A reference potential terminal connected to or in common with each of the first circuit unit and the second circuit unit;
A direct current application terminal capable of connecting a power source for applying a direct current or a direct voltage to the first magnetoresistive element of the first circuit unit and the second magnetoresistive element of the second circuit unit, respectively, or in common; With
The first circuit unit includes a first magnetoresistive element including a magnetization fixed layer, a magnetization free layer, and a spacer layer sandwiched therebetween, and a first conductor connected to one end of the first magnetoresistive element And comprising
The first conductor has a first end of the first conductor connected to a high-frequency current input side so that a high-frequency current flows in a branched manner with respect to the first magnetoresistive element and the reference potential terminal; A second end of the first conductor is connected to the reference potential terminal;
The second circuit unit includes a second magnetoresistive element including a magnetization fixed layer, a magnetization free layer, and a spacer layer sandwiched therebetween, and a second conductor connected to one end of the second magnetoresistive element And comprising
The second conductor has a first end of the second conductor connected to the input side of the high-frequency current so that a high-frequency current flows in a branched manner with respect to the second magnetoresistive element and the reference potential terminal, A magnetoresistive effect device, wherein a second end of the second conductor is connected to the reference potential terminal.   2. The magnetoresistive device according to claim 1, wherein a counter electrode connected to an end portion of the first magnetoresistive element facing the first conductor and the second conductor are formed of a common metal layer. Effect device.   3. The magnetoresistive effect device according to claim 1, wherein the first magnetoresistive effect element and the second magnetoresistive effect element are in a parallel connection relationship with respect to the DC application terminal.   The magnetoresistive effect device according to claim 1 or 2, wherein the first magnetoresistive effect element and the second magnetoresistive effect element are in a serial connection relationship with respect to the DC application terminal. The magnetoresistance effect device according to any one of claims 1 to 4,
A magnetoresistive effect module comprising: a DC current source or a DC voltage source connected to the DC application terminal of the magnetoresistive effect device.

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